I remember a few years back someone suggested this very idea, a Dune TV series which each season devoted to a particular book. I dismissed the idea out of hand saying there's no way a network would agree to a minimum six season deal for such a show. Of course, now we have Game of Thrones doing such a thing, so I guess it is a practical idea after all.
On the one hand, the Dune novels are so complex that even the six hour miniseries which many consider the definitive adaptations of the novels have had to "trim the fat" so to speak. A season of ten episodes might actually be enough to properly service the novels. Although it would be quite the challenge, budget wise, though probably not more so than Game of Thrones. Although I don't watch Game of Thrones or read those books, I see them basically having the same challenges of creating a completely new world. The difference is instead of some sort of the pseudo-medieval GoT has going on, Dune also has a futuristic flair to its trappings, but that shouldn't be too much more difficult to pull off.
Sure, a Dune TV show could have potential, is probably the best way to try an adaptation. I really doubt another movie is going to happen and SyFy would probably only bother these days if it included giant shark hybrids (Sharktopus vs Dune Worm?). While there is certainly precedent for TV shows based on novel series now, I'll be surprised if it happens. Let's face it, you want Dune at its best, the novels are it.